In this research project, immunological aspect of the skin was studied from different viewpoints such as 1) T cells in the skin, 2) Langerhans cells (LC), 3) Keratinocytes (KC), 4) Fibroblasts (Fb) and 5)Hair. In this study the existence of T cells unique to the skin was proposed from clinical as well as basic mouse study. This would be very important in terms of the development of T cell mediated skin lesions such as cutaneous T cell lymphoma. LC was investigated as for their migration as well as maturation and/on activation by cytokines and haptens. The immunological regulation of KC was also studied with the relationship to the external stimuli such as bacteria, physical barrier destination. The participation of Fb and hair cycle in skin immunology was studied. Overall, this project revealed the importance of skin as an immunological organ and suggest more studies are necessary to reveal this.